NO. 2 DAWSON: MARINE RED ALGAE OF PACIFIC MEXICO 277 



near mouth of Rio San Telmo, Jan. ; D. 8763, Punta San Quintin, Jan.; 

 D. 9709, Bahia San Quintin, Apr.; D. 1216, Socorro, Apr.; D. 8656, 

 8829, Jan., D. 1193, Apr., Punta Baja; D. 1552, Bahia Ositos, near 

 Punta Maria, Apr. 



This species appears to be a common one in all of the areas of up- 

 welling to the north of Bahia Vizcaino. In the colder localities it may 

 be found intertidally near low water level, but it is more commonly 

 encountered in drift. 



The early stages in carposporophyte development have been observed 

 and found to agree closely with those reported by Sjoestedt (1926) for 

 Z. lanceolate. 



The irregular pinnate branching and segments of irregular width, 

 but tending to be broad and ligulate, are distinctive of this species. 



Zanardinula lyallii (Harvey) DeTonivar. ? 

 PI. 18, fig. 63 



Several sterile specimens occur in intertidal collections from En- 

 senada de San Francisco, Sonora (D. 575, 595, 597, Feb., D. 11025, 

 June), which correspond closely both in gross morphology and in struc- 

 ture with specimens from Puget Sound, Washington, recognized by 

 Setchell and Gardner (1903) as Prionitis lyallii f. densissima. These 

 Sonora specimens are unique among the zanardinulas of the Gulf of 

 California, and it seems improbable because of geographic remoteness and 

 marked ecological differences that they are actually conspecific with 

 plants of far northwestern United States. However, to point up this 

 interesting distributional problem a photograph is presented here of one 

 of the Gulf plants, and it is tentatively assigned to Z. lyallii awaiting 

 the collection of fertile material and further study of relationships. 



The specimen from Bahia Magdalena, Baja California identified by 

 Taylor (1939, p. 13) has been reexamined and found to be a sterile 

 example of a species of Gracilaria. The structure shows no resemblance 

 to that of Zanardinula. 



Zanardinula acroidalea (Setchell & Gardner) comb. nov. 



PI. 5, figs. 37-39 



Grateloupia acroidalea Setchell and Gardner 1924, p. 781, pi. 26, 

 figs. 45-46; Dawson 1944, p. 281. Prionitis kinoensis Dawson 1944, p. 

 284, pi. 67, fig. 1; Taylor 1945, p. 210. Zanardinula kinoensis (Daw- 

 son) Dawson 1945b, p. 94; Dawson 1949, p. 244. 



